Just thought I would lay this out here and see if anyone had any ideas. The car is a 1988 Olds Cutlass Supreme FI V6 2.8L (believe it or not). This car has had a history of idling and hesitation problems. First time this happened, the EGR was replaced and it ran fine afterwards. Second time, the ECM (main computer) was replaced and it ran fine afterwards. Third time, battery was replaced and the dealer said the IAC codes, etc and computer codes were lost ... had to be reprogrammed ... ran fine afterwards (by the way I think this is a bunch of crap). Fourth time, dirty fuel injectors and bore ... cleaned by the dealership ... ran fine afterwards. Only about 20K miles on the car since this was done. Fifth time, changed battery again ... was told that the computer codes, etc might relearn itself and be okay. It did and ran fine after about a week or so. Now it hesitates at about 20 to 35 mph under acceleration. Idle is fine and smooth. Does stumble / idle rough sometimes on startup in the mornings now. Sometimes it dies and has to be restarted. Has died down two times a while back when put in reverse. Car has fairly new Bosch platinum spark plugs and oxygen sensor. Also, the fuel filter has been replaced not too long ago ... AC Delco brand. Air filter is clean ... AC Delco brand. All major tune items have been done ... PCV valve etc. ANY IDEAS???? I am so sick of this car. This happens almost every year now. I went ahead and put in fuel injector cleaner made by Valvoline Syn Power with synthetic cleaners but no results yet. Only about 40 miles since I did that. I'm at a loss of what it could be. Car has about 97K miles. Engine has never been abused or roughly driven. Always good brand of gas is used with 89 or 93 octane (i.e. Chevron or Mobil) Thanks in advance.